/*
* srm_env.c - Access to SRM environment
* variables through linux' procfs
*
* (C) 2001,2002,2006 by Jan-Benedict Glaw <jbglaw@lug-owl.de>
*
* This driver is at all a modified version of Erik Mouw's
* Documentation/DocBook/procfs_example.c, so: thank
* you, Erik! He can be reached via email at
* <J.A.K.Mouw@its.tudelft.nl>. It is based on an idea
* provided by DEC^WCompaq^WIntel's "Jumpstart" CD. They
* included a patch like this as well. Thanks for idea!
*
* This program is free software; you can redistribute
* it and/or modify it under the terms of the GNU General
* Public License version 2 as published by the Free Software
* Foundation.
*
* This program is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place,
* Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <asm/console.h>
#include <asm/uaccess.h>
#include <asm/machvec.h>
#define BASE_DIR "srm_environment" /* Subdir in /proc/ */
#define NAMED_DIR "named_variables" /* Subdir for known variables */
#define NUMBERED_DIR "numbered_variables" /* Subdir for all variables */
#define VERSION "0.0.6" /* Module version */
#define NAME "srm_env" /* Module name */
MODULE_AUTHOR("Jan-Benedict Glaw <jbglaw@lug-owl.de>");
MODULE_DESCRIPTION("Accessing Alpha SRM environment through procfs interface");
MODULE_LICENSE("GPL");
typedef struct _srm_env {
char *name;
unsigned long id;
struct proc_dir_entry *proc_entry;
} srm_env_t;
static struct proc_dir_entry *base_dir;
static struct proc_dir_entry *named_dir;
static struct proc_dir_entry *numbered_dir;
static char number[256][4];
static srm_env_t srm_named_entries[] = {
{ "auto_action", ENV_AUTO_ACTION },
{ "boot_dev", ENV_BOOT_DEV },
{ "bootdef_dev", ENV_BOOTDEF_DEV },
{ "booted_dev", ENV_BOOTED_DEV },
{ "boot_file", ENV_BOOT_FILE },
{ "booted_file", ENV_BOOTED_FILE },
{ "boot_osflags", ENV_BOOT_OSFLAGS },
{ "booted_osflags", ENV_BOOTED_OSFLAGS },
{ "boot_reset", ENV_BOOT_RESET },
{ "dump_dev", ENV_DUMP_DEV },
{ "enable_audit", ENV_ENABLE_AUDIT },
{ "license", ENV_LICENSE },
{ "char_set", ENV_CHAR_SET },
{ "language", ENV_LANGUAGE },
{ "tty_dev", ENV_TTY_DEV },
{ NULL, 0 },
};
static srm_env_t srm_numbered_entries[256];
static int
srm_env_read(char *page, char **start, off_t off, int count, int *eof,
void *data)
{
int nbytes;
unsigned long ret;
srm_env_t *entry;
if (off != 0) {
*eof = 1;
return 0;
}
entry = (srm_env_t *) data;
ret = callback_getenv(entry->id, page, count);
if ((ret >> 61) == 0) {
nbytes = (int) ret;
*eof = 1;
} else
nbytes = -EFAULT;
return nbytes;
}
static int
srm_env_write(struct file *file, const char __user *buffer, unsigned long count,
void *data)
{
int res;
srm_env_t *entry;
char *buf = (char *) __get_free_page(GFP_USER);
unsigned long ret1, ret2;
entry = (srm_env_t *) data;
if (!buf)
return -ENOMEM;
res = -EINVAL;
if (count >= PAGE_SIZE)
goto out;
res = -EFAULT;
if (copy_from_user(buf, buffer, count))
goto out;
buf[count] = '\0';
ret1 = callback_setenv(entry->id, buf, count);
if ((ret1 >> 61) == 0) {
do
ret2 = callback_save_env();
while((ret2 >> 61) == 1);
res = (int) ret1;
}
out:
free_page((unsigned long)buf);
return res;
}
static void
srm_env_cleanup(void)
{
srm_env_t *entry;
unsigned long var_num;
if (base_dir) {
/*
* Remove named entries
*/
if (named_dir) {
entry = srm_named_entries;
while (entry->name != NULL && entry->id != 0) {
if (entry->proc_entry) {
remove_proc_entry(entry->name,
named_dir);
entry->proc_entry = NULL;
}
entry++;
}
remove_proc_entry(NAMED_DIR, base_dir);
}
/*
* Remove numbered entries
*/
if (numbered_dir) {
for (var_num = 0; var_num <= 255; var_num++) {
entry = &srm_numbered_entries[var_num];
if (entry->proc_entry) {
remove_proc_entry(entry->name,
numbered_dir);
entry->proc_entry = NULL;
entry->name = NULL;
}
}
remove_proc_entry(NUMBERED_DIR, base_dir);
}
remove_proc_entry(BASE_DIR, NULL);
}
return;
}
static int __init
srm_env_init(void)
{
srm_env_t *entry;
unsigned long var_num;
/*
* Check system
*/
if (!alpha_using_srm) {
printk(KERN_INFO "%s: This Alpha system doesn't "
"know about SRM (or you've booted "
"SRM->MILO->Linux, which gets "
"misdetected)...\n", __func__);
return -ENODEV;
}
/*
* Init numbers
*/
for (var_num = 0; var_num <= 255; var_num++)
sprintf(number[var_num], "%ld", var_num);
/*
* Create base directory
*/
base_dir = proc_mkdir(BASE_DIR, NULL);
if (!base_dir) {
printk(KERN_ERR "Couldn't create base dir /proc/%s\n",
BASE_DIR);
goto cleanup;
}
/*
* Create per-name subdirectory
*/
named_dir = proc_mkdir(NAMED_DIR, base_dir);
if (!named_dir) {
printk(KERN_ERR "Couldn't create dir /proc/%s/%s\n",
BASE_DIR, NAMED_DIR);
goto cleanup;
}
/*
* Create per-number subdirectory
*/
numbered_dir = proc_mkdir(NUMBERED_DIR, base_dir);
if (!numbered_dir) {
printk(KERN_ERR "Couldn't create dir /proc/%s/%s\n",
BASE_DIR, NUMBERED_DIR);
goto cleanup;
}
/*
* Create all named nodes
*/
entry = srm_named_entries;
while (entry->name && entry->id) {
entry->proc_entry = create_proc_entry(entry->name,
0644, named_dir);
if (!entry->proc_entry)
goto cleanup;
entry->proc_entry->data = (void *) entry;
entry->proc_entry->read_proc = srm_env_read;
entry->proc_entry->write_proc = srm_env_write;
entry++;
}
/*
* Create all numbered nodes
*/
for (var_num = 0; var_num <= 255; var_num++) {
entry = &srm_numbered_entries[var_num];
entry->name = number[var_num];
entry->proc_entry = create_proc_entry(entry->name,
0644, numbered_dir);
if (!entry->proc_entry)
goto cleanup;
entry->id = var_num;
entry->proc_entry->data = (void *) entry;
entry->proc_entry->read_proc = srm_env_read;
entry->proc_entry->write_proc = srm_env_write;
}
printk(KERN_INFO "%s: version %s loaded successfully\n", NAME,
VERSION);
return 0;
cleanup:
srm_env_cleanup();
return -ENOMEM;
}
static void __exit
srm_env_exit(void)
{
srm_env_cleanup();
printk(KERN_INFO "%s: unloaded successfully\n", NAME);
return;
}
module_init(srm_env_init);
module_exit(srm_env_exit);
